FYI, Mark Adler has released a new version of pigz, the parallel gzip
program, and it now has an --rsyncable option -- one that is apparently
even better than the prior (patched) version of gzip from Debian. If
you're using rsync to copy changed gzip files over the internet, you may
want to see if using --rsyncable helps to improve your transfers (since it
can re-sync inside the file). In any case, pigz is certainly much faster
compressing files than gzip (when using a multi-core machine).